Was you preamp modified?
The original Wolze used a 12au7 "type" along with EF86.
DeKay
The original Wolze used a 12au7 "type" along with EF86.
DeKay
... How to select tubes for line level preamp ...
DeKay Did you /do you have one of these - it’s been "rumored" there was less than 10 ever available: any opinion /review from your memory? If you can explain please what is the differrence between a 12au7 and a 12ax7 (other than having this one Wolze piece - I have no reference to tubes what so ever). Thanks... |
The 12ax7 has approx. 5 times the gain of a 12au7 "type" tube. Never seen/heard you preamp but, from what I recall about it an unusual 12au7 type was used. I may have run across the Wolze when researching tubes for my "early" Bottlehead Foreplay 12au7 based preamp years ago, but I do not recall the specifics (certain that it was not a 12ax7 though). I'll try searching the old Bottlehead forums tomorrow to see if I can come up with the 12au7 equivalent that I researched (like 15 years ago;-) This said, if it has been changed/modded this will be a mute point. I've rolled the 86 tubes in something (thinking a vintage Pilot 690 preamp/tuner), but again I do not recall specifics as this was a long time ago. Anyway, if it does end up using a 12au7 I'm familiar with gobs of old production types and can chime in @ that point. DeKay |
insearchof, The most important characteristic of a tube is noise. There is a lot of variability between tubes even of the same manufacturer. Noisier tubes decrease dynamic range and can interfere with quiet passages. RAM Labs tests their tubes individually and rates them as standard, low noise and super low noise. They are priced accordingly. I use their SLN tubes in my ARC phono amp and they are an easy 10 dB quieter than the tubes that came with the unit. http://www.tubeaudiostore.com/ |